Method of making closure caps



mm llil mmm May 26, 1931. w. P. WHITE mmaon OF MAKING CLOSURE CAPS FiledMay 21. 1928 Patented May 26, 1931,

UNITED STATES WILLIAM .P. WHITE, OF CHICAGO, ILLINOIS, ASSIGNOR TOCHICAGO, ILLINOIS, A CORPORATION OF DELAWARE PATENT: OFFICE WHITE carCOMPANY, or

METHOD OF MAKING CLOSURE CAPS Application filed May 21, 1928. Serial No.279,390.

This invention relates to manufacture of closure caps of the typeemployed for closing vessels or receptacles, such as jars, cans,tumblers, bottles, and the like, for the retention and preservation oftheir contents.

In my copending application Serial No.

340,414 filed on February 16, 1929, as a division of this application, Idescribe and claim an improved closure cap possessing certain featuresby virtue of which it may be applied with facility to the Vessel, willform a secure air-ti ht seal effective to retain the contents of t evessel, prevent pollution thereof and hold a vacuum in the vessel, maybe removed easily without destruction or mutilation of either the vesselor the closure itself, is susceptible of repeated reuse to form aneffective closure and seal for a vessel, and has various otheradvantages from the standpoint of manufacture, use by the packerfand useby the consumer.

One object of the present invention is the provision of an improvedmethod whereby a closure cap having the characteristics and advantagesabove specified may be manufactured rapidly and in large quantities atminimum expense and with uniformity in the construction and design ofthe caps produced. v

Another object is the provision of an improved method for formingclosure caps with elastic sleeve gaskets.

Other and further objects, features, and

advantages of the invention will be pointed out or indicated hereinafteror will appear to one skilled in the art upon an "understand-s ing ofthe invention-or its employment in practice.

In the accompanying drawings forming a part of this specification areillustrated certain steps in the practicing of the method and certainstructural features of a cap embodying the invention, but it isto beunderstood that these may be departed from in certain details in thepractice of the invention.

In said drawings: I Fig. 1 is a diametrical sectional elevation ofa capportion of a closure for a packing vessel; V

of the package.

Fig. 2 is. a diametrical section of a gasket forming a part of suchclosure;

Fig. 3 is illustrative of an operation performed in assembling thegasket in the cap portion;

Fig. 4 is a diagrammatic plan view of certain elements of apparatuswhich may be employed for constricting or circumferentially compressingthe gasket for positioning it in the cap portion;

Fig. 5 is a'diametrical sectional elevation showing the cap portion withthe gasket inserted therein;

Fig. 6 illustrates a similar diametrical sectional elevation of theclosure and an operation. in the method for positioning the insertedgasket in the cap portion;

Fig. 7 is a part sectional elevation of a receptacle and a closure capillustrating the relative position of same at one stage in the operationofplacing the closure on the vessel;

Fig. 8 is a similar part sectional elevation illustrating relativepositions of the closure portions and the vessel at a laters'tage 1n thesealing operation, and

Fig. 9 is a similar part sectional elevation illustrating therelationship of the closure parts and the vessel in the sealed package.

In the packing of various materials such as food stuffs. which it isdesired to seal airtight, and which itmay be desired to pack invacuoandto subject to a sterilizing heat after sealing, certain features ofthe package and of the closures therefor are of prime importance. Forexample, it is of importance that the closure be easily applied, so thatthe packing may be carried on rapidly and withoutnecessitating theemployment of heavy mechanical pressures which might distort or fracturethe closure itself or-the vessel to which it is applied. Likewise, it isof-importance' that the closure form a. close air-tight seal on thevessel so that the contents of the package may be properly preserved,incident to which it is necessarythat the connection of the closure andthe vessel be such that the formeris securel retained in place incidentto handling and shipping Moreover, it is quite desirable that theclosure be susceptible of remov- 13o al with facility by the consumerwithout injury to it or the vessel, so that it maybe continued in use asan effective closure in the event it is desired to keep some of thecontents'in the vessel after it has been originally opened. Thecloseness of the seal and the secure retention of the closure on thevessel are of particular importance also in connec- 4 tion with theprocessing or sterilizing of the sealed package by heat, due to the factthat the heat generates pressures within the pack.- age which tend todisplace the closure or render the seal leaky, and thus ofieropportunity for pollution of the contents. A closure which meets theserequirements in a veryeffective manner is disclosed in my copendingapplication referred to above, and the method of manufacture hereindescribed may be utilized to advantage in the manufacture of closures ofthat and similar types.

As a first operation in the method of manu facture, a suitably shapedblank of ductile and resilient sheet material, such as sheet metal, isformed, as by punching, drawing and spinning operations, into a caphaving the top portion 10, customarily of circular form, with thedepending skirt having a holdin portion 11, preferably cylindrical, anda aring portion 11 which terminates at an intumed flange 12. A sleevegasket 14, is formed of a compressible elastic material, such as a firmrubber composition, as by cutting ofi' sections of rubber tubing. Theoutside circumference of this gasket is substantially in excess of theinner circumference of the holding part 11 of the cap, and

may be in excess even of the maximum mternal circumference of theflaring part 11. The cap and the gasket are formed with reference toeach other in, such respect that the width of the flange l 2 will besufiicient to cover the end of the gasket. 'The gasket being so formedand being suitably glycerized or similarly treated to give it the propersurface finish, is then' subjected to a constricting deformation orcircumferential compression while in a. substantially cylindrical orannular form. This step is illustrated in Fig. 3, and may beaccomplished by positioning the gasket about a cylindrical mandrel Mwhich is of a circumference substantially smaller than the innercircumference of the gasket and also substantially less than the innercircumference of the holding part 11 of the cap. Constricting pressure1s then ap lied to the outer circumferential side 0 the gasket as bymeans of movable constricting members C operated in such fashion as tocompress the gasket radially and circumferentially and press it againstthe circumferential surface of the mandrel. These canstricting membersmay be asociated with one another in such fashion as to completelyencompass the gasket, as illustrated in Fig. 4, and manipulated with aninvolute movement so that they exert pressures both cir-.

though thus compressed and constricted to a erence than that of itsoriginal size, the gasket retains its elasticity. While the gasket isheldin this constricted size and substantially ly cylindrical form, thecap is brought into coaxial relationship with it, as illustrated in Fig.3, whereupon the constricting pressure issuddenly released while at thesame'time the cap is instantly pressed down in envelopsize which issubstantially less in circumf ing relationship to it, so that when thegasket reacts elastically from the compression, it will be caught withinthe circumscribing skirt portion of the cap., Thereupon, the gasket andthe cap will occupy approximately the relationship illustrated in Fig.5. Now, in order to completely position the gasket in the cap with thelower edge of the gasket entirely seated above the flange 12 and theupper edge properly spaced from the 'top of the cap, and-to give thegasket the desired flare or tapering contour, I

the lower portion of the gasket is submitted to a rubbing operation soapplied as to force the entire lower edge to a position overlyin theflange 12. This rubbing pressure is pre erably applied to the gasket inboth u ward and outward directions. It may e applied very convenientlyand effectively by a spinning operation, as by means of a conicalspinning wheel-W which is rotated on its axis and which has some lowribs W, the wheel with the ribs-being of such size that it may enterpart way within the gasket and contact the lower corner portion thereof.When the cap with the asket is pressed lightly on the wheel asillustrated in Fig. 6, the spinning wheel will apply rubbing pressurescircumferentially, upwardly and outwardly to the gasket, and move thegasket upwardly in the cap and dispose the lower margin portion thereofin a position overlying the flange 12, incidentally giving the gasketthe desiredflaring or taperin form. A proper spacing of the" upper e eof the gasket from the top of the cap is o importance in view of thevariations which occur in the circumferential size and form ofthe'recepltacles which are availand expected in any lot of a givencommercial size rating. In order for a given closure to be capable ofuse on any vessel within the expected variations, it is necessary thatit be qualified to accommodate such variations, from minimum to maximum,without detri ment to its sealing efi'iciency. Hence, it is necessarythat the gasket be of sufiicient thickness to form an effective seal ona vessel of minimum size, and at the same time that the closure be ableto take a vessel of maxi- -mum size, within the range of the expectedvariations of vessels of a given size rating. One condition which it isimportant to avoid in the sealing of the vessel is the pinching of aportion of the gasket material between the rim of the vessel and the topof the cap. Such pinching prevents the complete seating of the closureon the vessel, and hence may decrease the area of sealing contactbetween the outer wall of the vessel and the gasket. Moreover, thepinching of some of the elastic gasket material between the rim of thevessel and the top of the cap tends to force the cap off after thepressure of the sealing mechanism has been removed from the cap. Thus,the security of the seal is rendered uncertain if there is pinching ofthe gasket as just pointed out; In order for a closure to be thoroughlyreliable, therefore, it must be proof against this pinching of thegasket By employing a gasket of such length and positioning it in thecapin such relationship that there is a substantial space between thetop of the gasket and the top of the cap, I am enabled to use a cap ofsufficient size and a gasket of sufficient thickness to accommodate allvariations within the commercial tolerances of a rated vessel sizewithout sacrifice of security or certainty-of the seal. The method abovedescribed permits the closures to be turned out rapidly with the properspacing of the gasket from the top of the 1 cap.

It will be observed that the gasket is still retained in acircumferentially compressed condition,- and thereby will retain itsdesired position in the cap, although it is in no manner bound thereto.Hence the closure is ready to be applied to a vessel. The completeclosures may be packed conveniently in cartons, one resting partlywithin another.

By the method above described, the caps may be formed rapidly and inlarge quantities with strict uniformity in size and design, it beingunderstood, of course, that the method is not limited to the formationof caps of the particular design illustrated in the drawing.

What I claim is:

1. A method of making a closure for vessels comprising forming a capwith an annular skirt portion having 'a holding part and a flaring partterminating at an inturned marginal flange, forming a sleeve mitting thegasket of compressible elastic material of greater circumference thansaid holding part, subjecting the asket while in substantiallycylindrical orm to circumferential compression to reduce its size to acircumference less than that of the holding part, inserting the gasket,as thus compressed, within the skirt portion of the cap, releasing thegasket to the constraining retention of the skirt portion, and pressingthe lower portion ofthe} gasket upwardly to a position overlying themarginal flange of the cap.

2. A method of manufacturing a closure comprising forming a cap of sheetmaterial with an annular skirt portion having a flaring lower partterminating in an in-turned flange, forming a sleeve gasket ofcompressible elastic material and of a circumferential size exceedingthe inner circumference of said flange, compressing the gasketcircumferentially to a size permitting its insertion into the skirtportion, inserting the gasket into the skirt portion while socompressed, permitting the gasket to expand elastically from itscompressed size into contact with the skirt portion, and then rubbingthe lower portion of the gasket outwardly to a position against theflaring part and above the flange.

3. A method of manufacturing a closure comprising forming a sheet metalcap with an annular skirt portion having a substantially cylindricalupper part, and outwardly flaring lower-part terminating at an inturnedflange, forming a sleeve gasket of compressible elastic material with acircum ferential extent exceeding the inner circumference of saidcylindrical part, compressing the gasket circumferentially to an annularform and size permitting its insertion within said cylindrical part,inserting the gasket within the skirt portion while so compressed andpermitting it to expand elastically against the skirt portion, and thenpressing the gasket into the cap to position its lower margin above thein-turned flange while its upper port-ion is within the said cylindricalpart.

4. A method of manufacturing a closure which comprises forming a sheetmetal cap with an annular skirt portion which has a lower partterminating in an in-turned flange and flaring from an upper part ofsmaller circumferential extent, forming a sleeve gasket of compressibleelastic material with a circumferential extent exceeding that of saidupper part, elastically deforming the gasket by compressing itcircumferentially in substantially annular form to a circumferentialsize permitting its insertion within the skirtportiominserting thegasket within the skirt portion while so compressed, pergasket to expandelastically into contact with the skirt portion, and applying spinningpressure to the lower portion of the frs gasket to move it to. aposition overlying the marginal flange of the cap.

5. A method of assembling an elastic sleeve gasket in the skirt of aclosure cap, which comprises setting up elastic compression in thegasket by applying to it peripheral constricting pressure and supportingit against collapsing inwardly, disposing the closure cap in coaxialassociation with the constricted gasket, releasing the constrictingpressure and at the same time moving the cap skirt in an axial directioninto encompassing association with the gasket, thereby permitting thegasket to expand by its own elasticity into peripheral contact with theinner wall of the skirt.

6. A method of assembling an elastic sleeve gasket in an annularlyflanged closure comprising elastically deforming the gasket to reduceits radial dimensions, inserting it within the compass of the closureflange, and

spinning portions of the gasket outwardly into peripheral contact withthe inner surface of the flange.

7. A method of making a vessel closure which comprises providing a capwith an annular skirt having portions curved on a common radius andaflared portion of larger radius, providing an elasticsleeve gasket ofcircumferential extent greater than the inner wall of the skirt,constricting the gasket to a size permitting its insertion into thecompass of the skirt, inserting -it axially within the compass of theskirt, and spinning portions of the gasket into peripheral contact withthe flared portion of the skirt.

8. A method of assembling a closure which comprises providing a closureart in the form of an annular skirt, providmg an elastic sleeve gasketof circumferential extent greater than that of the inner'surface of saidskirt, constricting the gasket to reduce its circumferential extent andsupporting it against collapsing inwardly, inserting the constrictedgasket within the compass of the skirt, and releasing the gasket topermit it to expand by its own elasticity into peripheral contact withthe skirt.

9. A method of assembling an elastic sleeve gasket in an annular closureskirt, which comprises applying inward pressure to peripheral portionsof the gasket to reduce its extent and set up elastic compression in it,applying support to inner surface portions of the gasket to limit theirinward displacement, inserting the reduced gasket within the compass ofthe skirt, and releasing the gasket to the constraining support of theskirt. 7

In testimony whereof I have hereunto subscribed my name. 7 p

WILLIAM P. WHITE.

